This invention relates to a polybutene composition used for a fat-liquoring substance or agent, more particularly to a fat-liquoring composition for leather containing a neutralized polybutene sulfonation product, a polybutene and fatty acid salt or salts.
Heretofore, natural oils have been used as a fat-liquoring substance for leather. For example, marine oils such as cod oil, shark oil, sperm oil and their sulfation and sulfornation oils, and land oils such as neat's foot oil, wool wax and their sulfation and sulfonation oils have been employed alone or as a mixture thereof. Further, as vegetable oils, olive oil, rapeseed oil and their sulfation and sulfonation oils also have been used alone or as a mixture thereof. However, these fat-liquoring substances prevailing in natural oil ingredients are unstable in qualities owing to the occurrence in liquored leather of malodor, yellowing and spew, etc. Further, there was a shortage of raw materials therefor resulting from the exhaustion of natural resources. Thus, the development of production means of fat-liquoring substances principally comprising petrochemical derivatives (referred to as synthetic oil(s) hereinunder) has been promoted recently. For example, in Japanese Patent Bulletin No. 51-44161 (Japanese Patent Publication 51(1976)-44161), a fat-liquoring composition comprising 100 parts by weight of a polybutene, 5-100 parts by weight of a neutralized polybutene sulfonation product and a non-ionic surface active agent respectively added is disclosed.
However, such a fat-liquoring agent mainly comprised of synthetic oils has the following disadvantages, and a satisfactory fat-liquoring substance having a major content of synthetic oils has not yet been found.
That is to say, a fat-liquoring substance containing neutralized polybutene sulfonation products has such defects that when the neutralized polybutene sulfonation product is employed without hydrolysis, a finishing product of stable quality cannot be obtained because the finished product becomes gradually acidic to promote the decomposition of the neutralized product, and because the emulsion of the finished product is demulsified. This is deemed to be due to the decomposition of alkane-sultone compounds included in the neutralized polybutene sulfonation product. In order to eliminate the above defects by previously decomposing the alkane-sultones, the neutralized polybutene sulfonation product may be hydrolyzed, however, in this case, hydroxyalkanesulfonates which are very difficult to dissolve in water are formed. Accordingly, the hydrolyzed products of neutralized polybutene sulfonation products alone are not satisfactory for preparing an excellent and stable emulsion suitable for a fat-liquoring agent. For the reason, in order to obtain an excellent emulsion therefor, the addition of non-ionic surfactants becomes indispensable, as seen in Japanese Patent Bulletin No. 51-44161.
Nevertheless, a fat-liquoring substance obtained by the addition of non-ionic surfactants has such fatal disadvantages that the commercial value is low because the feel of leather treated therewith is hard and the handling thereof is very inferior in comparison with that of leather treated and finished with a fat-liquoring substance comprising natural oils as a raw material. This results from a large absorption of the surfactant in the leather and absorption thereby in the leather of a greater part of neutral oils included in the fat-liquoring substance.
In such circumstances, many attempts have been made in the field concerned heretofore in order to develop an improved fat-liquoring substance without various disadvantages described above, however such attempts have not been crowned with success until now.